<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
     <h1 id="box">这是一个盒子</h1>
     <script type="text/javascript" src="js/base.js"></script>
<script type="text/javascript">
// console.log(document.getElementById("box"));

  console.log($("box"));

</script>
</body>
</html>